The Economic Operation of Common Coupling Groups of Distribution Transformer

2014 ◽  
Vol 521 ◽  
pp. 288-291
Author(s):  
Yu Sheng Quan ◽  
Xin Zhao ◽  
Hua Gui Chen ◽  
En Ze Zhou

Based on the method of symmetrical components of D, 11 and Y, o distribution transformer coupling two different effects of different magnetic circuit coupled to the three-phase system with a system-generated analysis and comparison. Analysis of the difference between the two groups of different connections on the transformer structure. Described in the single-phase short circuit fault clearing, 3n harmonic current suppression and affordability aspects of single-phase unbalanced load, D, ll coupling transformers are significantly better than Y,0 coupling transformer. This has necessarily important for the study of energy loss reduction.

2020 ◽  
Vol 4 (2) ◽  
pp. 53-59
Author(s):  
Cilvia Calnela ◽  
Suyitno ◽  
Imam Arif Raharjo

This study aims to determine the difference in short circuit current with manual calculation and ETAP 12.60 Simulation  in to know the suitability of capacity circuit breaker Substasion 150/20 kV at Gandul. The used method is qualitative descriptive method. The subject that will be studied is short circuit on the substation 150/20 kV Gandul Cinere. The research was conducted by using is manual calculation and software ETAP 12.60 simulation. The results obtained is differences of the short circuit current is not significant between the manual calculation and software ETAP 12.60 simulation in three conditions include 0.572% for the conditions of short circuit fault of one phase to ground, 0.884% for the conditions of short circuit fault of phase to phase and last 0.884% for the short circuit fault of three phase. Furthermore, the result of the calculation of the short circuit current will be used as an indicator of a determinant of the suitability of the capacity circuit breaker substation 150/20 kV at Gandul , obtained that a comparison of the rating circuit breaker installed (existing) is great against the result of the election of the rating circuit breaker base on manual calculation. So it can be concluded that the circuit breaker beinstalled on the substation 150/20 KV at Gandul, has a capacity that suits your needs and still fit for use. ABSTRAK Penelitian ini bertujuan untuk mengetahui perbedaan besar arus hubung singkat antara perhitungan manual dan simulasi ETAP Power Station 12.6 serta untuk mengetahui kesesuaian kapasitas pemutus tenaga GI Gandul 150/20 kV. Metode yang digunakan adalah deskriptif kualitatif. Subjek pada penelitian ini adalah arus hubung singkat pada Gardu Induk 150/20 kV Gandul Cinere. Penelitian dilakukan menggunakan perhitungan manual dan simulasi software ETAP Power Station 12.6. Hasil penelitian diperoleh bahwa perbedaan hasil arus hubung singkat yang tidak signifikan antara perhitungan manual dan simulasi software ETAP Power Station 12.6 dalam tiga kondisi meliputi 0.572% untuk kondisi gangguan hubung singkat salah satu fasa ketanah, 0.884% untuk kondisi gangguan arus hubung singkat fasa ke fasa dan terakhir 0.884% untuk gangguan arus hubung singkat tiga fasa. Selanjutnya, hasil perhitungan arus hubung singkat tersebut akan digunakan sebagai indikator penentu kesesuaian kapasitas pemutus PMT (Circuit Breaker) GI Gandul 150/20 kV, diperoleh bahwa perbandingan rating pemutus PMT yang terpasang (existing) lebih besar terhadap hasil pemilihan rating pemutus PMT berdasarkan perhitungan manual. Sehingga dapat disimpulkan bahwa pemutus tenaga yang terpasang pada di GI Gandul 150/20 kV memiliki kapasitas yang sesuai dengan kebutuhan dan masih layak digunakan.


Author(s):  
Deni Almanda ◽  
Juniyanto Juniyanto

Pada saat terjadi gangguan hubung singkat di saluran transmisi Gardu Induk Plumpang, rele jarak berfungsi sebagai proteksi utama. Penelitian ini bertujuan untuk mengetahui pengaruh kompensasi impedansi urutan nol (kzn) terhadap kehandalan sistem proteksi rele jarak (distance relay) pada penghantar harapan indah di Gardu Induk Plumpang. Setting rele jarak yang didapatkan dari PT PLN (Persero) UPT Pulogadung disimulasikan menggunakan alat uji Omicron. Hasil simulasi gangguan hubung singkat satu fasa, gangguan hubung singkat dua fasa, dan gangguan hubung singkat tiga fasa menggunakan setting lama Z1 = 2.58 Ω, Z2 = 3.87 Ω, dan Z3 = 7.30 Ω, kZn = 0.93 Ω < -0.4° rele jarak tidak bekerja selektif, maka dilakukan resetting. Hasil resetting rele jarak yaitu Z1 = 2.58 Ω, Z2 = 3.87 Ω, dan Z3 = 7.30 Ω, kZn = 0.68 Ω < -0.6°. Setelah dilakukan resetting dan disimulasikan gangguan hubung singkat satu fasa, gangguan hubung singkat dua fasa, dan gangguan hubung singkat tiga fasa, rele jarak bekerja secara handal. Kesimpulannya kZn dapat mempengaruhi kehandalan sistem proteksi rele jarak pada penghantar harapan indah di Gardu Induk Plumpang.In the event of a short circuit in the transmission line of the Plumpang Substation, the distance relay serves as the main protection. This study aims to determine the effect of zero sequence impedance compensation (kzn) on the reliability of the distance relay protection system at the Harapan Indah conductor at the Plumpang Substation. The distance relay setting obtained from PT PLN (Persero) UPT Pulogadung was simulated using the Omicron test tool. Simulation results of single phase short circuit, two phase short circuit, and three phase short circuit using the old setting Z1 = 2.58 Ω, Z2 = 3.87 Ω, and Z3 = 7.30 Ω, kZn = 0.93 < -0.4° relay distance does not works selectively, then resetting is done. The results of resetting the distance relay are Z1 = 2.58 Ω, Z2 = 3.87 Ω, and Z3 = 7.30 Ω, kZn = 0.68 < -0.6°. After resetting and simulating single-phase short circuit, two phase short circuit, and three phase short circuit fault, the distance relay works reliably. In conclusion, kZn can affect the reliability of the distance relay protection system on the beautiful hope conductor at the Plumpang Substation.


Author(s):  
N. F. M. Yasid ◽  
A. A. Alawady ◽  
M. F. M. Yousof ◽  
M. A. Talib ◽  
M. S. Kamarudin

Different techniques for monitoring the transformer condition are continuously discussed. This is due to the fact that transformers are one of the most expensive components in the power system network. Not to mention the cost to fix any failure occurred in the transformer that have becoming more expensive nowadays. Frequency response analysis (FRA) is found to be the best method to monitor the transformer reliability. This paper presents a continuation of study presented in previous paper [1]. The study performed a laboratory test to show that the response of a normal winding phase A can be affected by short circuit fault which occurred at LV winding phase a, b, and c. To further investigate, current paper performed FRA measurement and applied fault on all phases. The same procedure is repeated on a distribution transformer to verify the findings. This is to examine the effect of fault at winding of other phases to the response of measured phase.


Author(s):  
Azzeddine Ferrah ◽  
Mounir Bouzguenda ◽  
Jehad M. Al-Khalaf Bani Younis

Large and small single-phase and three-phase induction motors are commonly used in industrial applications. The present work represents an attempt towards the design of a high accuracy system for the measurement of fractional horsepower (FHP) induction motor losses and efficiency. The calorimeter designed and built is capable of measuring heat losses of up to 1 kW with an overall accuracy better than 3%. During all tests, ambient temperature, humidity, motor speed and motor frame temperature were recorded using precise digital instruments. The inlet, outlet temperatures and resulting losses were recorded automatically using a high accuracy 12-bit data acquisition system. The preliminary results obtained demonstrate the suitability of the designed calorimeter for the accurate measurement of losses in FHP induction motors.


2021 ◽  
Vol 1 (1) ◽  
pp. 23-34
Author(s):  
Mansur A. SHAKIROV ◽  

A topological equivalent circuit for a three-phase three-core transformer reflecting the spatial structure of its magnetic system is developed. Owing to this approach, it became possible to represent the magnetic fluxes of the magnetic circuit’s all main sections and the apertures for each of three phases directly in the circuit in the absence of the windings’ neutral wires. The circuit is constructed by stitching together the anatomical circuit models of single-phase transformers obtained in the previous parts with taking into account the relationships between the fluxes at the junctions of the phase zones in iron. Its validity is confirmed by the rigor nature of the physical and mathematical relations for idealized transformers with infinite magnetic permeability of iron and simplified magnetic field patterns, which corresponds to the generally accepted approach with neglecting the magnetization currents. The difference lies in the fact that the developed model takes into account the heterogeneity of magnetization in different parts of the magnetic circuit with allocating more than 30 sections in the iron and apertures. The transition to the model of a real three-core transformer is carried out by adding four nonlinear transverse magnetization branches in each extreme phase zone and eight branches in the central phase zone to the idealized equivalent circuit. It is shown that in cases of winding connections without neutral wires, there is no flux of the Poynting vector in interphase zones in any unbalanced mode. In this case, the problems connected with the occurrence of fluxes exceeding the no-load fluxes under the conditions of symmetric and asymmetric short circuits, as well as the occurrence of buckling fluxes in these modes in the region outside the transformer iron, are solved.


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